Refrigerating machine



Nov. 19, 1929. c. STEENSTRUP REFRIGERATING MACHINE Filed Feb. 5, 1927 2 Sheets-Sheet ,InvenTor Ch risricm fife-ensfru Pa bg Nov. 19, 1929. c. STEEN STRUP 1,736,635 i REFRIGERATING MACHINE Filed Feb. 5, 1927 2 Sheets-Sheet 2 ll i% g 73 Inveni'or ChrisTicm STeensTrup,

g y um Hi 5 ATTorne mama Now.19,1929

UNITED STATES PATENT OFFICE cnnrs'rrnn srnnns'raur, or scimivncmmz, new YORK, 'assienon 'ro GENERAL ELEC- 'rnrc column, A conrona'rron or NEW YORK BEFRIGEBATING MACHINE Application filed February 5, 1927. Serial No. 166,212.

- My invention relates to refrigeratin ma- 7 chines and particularlyto electrically riven refrigerating machines adapted for domestic 'tisfe. An ob ect of my invention is to provide an improved refrigerating machine of this character having various features of construction which result in superior performance characteristics such as quiet running and freedom from stalling or overloading of he dr1v1ng motor when running conditions v are to be resumed after a shut down.

.My invention'will be better understood .from the following description taken in coni'nection with the accompanyin drawing, and

' c aimed in my cogendin No. 148,266, filed ovem er 13,1926,ass1 ned its scope will be ed claims. I

Referring to the drawing, Fig. 1 is a vertical cross sectional view of a refri erating machine involving my invention; ig. 2 is a transverse cross sectional view of the same taken on the line 2-2 of Fig. 1; Figs. 3 and 4 are fragmentary cross sectional views of the mechanism drawn to a larger scale; Fig.

5 shows the exhaust valve and associated pointed out in the appendparts drawn to a still larger scale; Fig. 6 is a fragmentary cross sectional view showing the oil'pump; and Fig. 7 is a erspective view of the main compressor an oil pump pistons.

In the drawing I have shown at 1 the upper portion of a refrigerator box, the top which has an opening closed by the cover 2. Secured to the cover 2 and occupying a position within the box is the evaporator 3, the s ecific construction of which is disclosed and application, Serial to the same assignee as the present app ica-.

I ativel, massive construction insure a gas tig oil pump 9 and the driving motor 10, to-' gether with the driving connections. valves, etc. therebetween. The various parts of the operatin mechanism are secured together by the frame 12 forming a separable unit. For supporting this unit mechanism I provide the frame 12 with lugs 13 preferably three in number and equally spaced and between these lugs and the base 4 I provide coil springs 15. The opposite ends of these springs are firmly secured respectively to the lugs 13 and to the base 4 by being threaded over grooved plugs 16 fastened to those members. The three springs thereby constitute a three oint support for the operating mechanism, t e strength of the sprin 5 being such that the mechanism is free to vi rate as a whole without transmitting those vibrations to the enclosing casing.

The casin which as stated above, is gas tight, is su jected to the pressure of the compressed refrigerant, the compressor exhausting into the castingland from the casing the compressed and eated gas escapes through pipe 20 into the condenser coil 21. The other end of this coil connects with the float chamber 22 from which the condensed refrigerant is fed tothe evaporator through inlet pipe 23. The casin is surrounded by aseries of fins 25 by whic the condenser coil f is supported and which being in cod-then mal connection with the coil and with the casmg serve to increase the heat dissipation from both. Connection is made in part between the inlet of the compressor and the outlet of the evaporator by the pipe 26 which after seeing throu h the base 4. extends up into t is belland is ormed into one ormore turns 27 about the mechanism to enable it to yield readily to the vibrations of the mechanism. The turns 27 in this pipe are formed to slope u wardly from the evaporator so that shoul a slug of liquid be drawn up into it or run into it in the event that the machine is tipped sufliciently, the liquid will natural- 1y drain back into t e evaporator. Moreover, 811109 the coil is surrounded by the compre gas, its tem rature "is such that smallquantities of i uid refrigerant that maybe drawn up wil be vaporized before reaching the compressor. For damping out vibrations that may travel along the turns 27 I tie the turns together as shown at"28 preferably by bands of silk as this material does not afiect and is not effected by the sulphur dioxide which I prefer to use as the refrigerant.

The pipe 26 through which the refrigerant gas is drawn from the evaporator terminates in a valve support 30 (see Fig. 4) containing the valve 31 comprising a loosely fitting plunger body portion and a. conical end portion which when the mechanism is at rest is yieldingly withdrawn from its seat 32 by the coil spring 33. The upper portion of the supt port 30 is enclosed by a dome-shaped casing 34 forming therewith a surge chamber or reservoir 35. One side of the valve seat connects by passage 36 with pipe 26 and the other side connects with the chamber 35 by two restricted passages 37. The valve supa port 30'is secured in a gas tight manner by screws 38- to the bottom plate 39 forming a part of the'frame 12 and in which is the inlet port 40 of the compressor. The valve support 30 has three openings 41, one only of which is shown, which connect with the passage 42 in plate 39 leading to port 40, a screen 43 being providedin passage 42 to prevent any dirt or metal chips that may be in the system from entering the compressor. In the normal operation of the machine the valve 31 remains in the full open position illustrated, being so held by the spring 33 that the gas taken by the compressor must pass the restricted openings The compressor comprises the oscillating cylinder 45 mounted in trunnions 46 and a piston 47 journalled on the wrist pin48. The drive shaft 49 which is journalled in the frame 12 carries the wrist .pin 48 at its lower end and is secured at its upper end to the rotor of the driving motor 10. For var1ous obvious reasons it is desirable to operate the mechanism at a relatively the gas may take place and second, by the' combined provision of the chamber 35 and the restricted openings 37 through which the gas enters the chamber in substantially steady streams.

In ordinary use, domestic refrigerating machines of the motor driven type such as disclosed herein are adapted to operate intermittently, the running and quiet periods besta'i'ting the mechanism after each period of inactivity, means have been provided for unloading the compressor by admitting gas pressure to the rear of the piston so that the pressure on the two ends. of the piston would be substantially balanced, this condition con"- tinuing until the driving motor has ,attained substantially its normal speed. In my copending application, Serial No. 109,960, filed May 18, 1926, and assigned to the same assignee as the present application, I have shown unloading means which responds to the pressure of the lubricating oil which is pumped only when the compressor is in operation. As in the aforesaid application, the compressor cylinder 45 has the small oil pump bore 52 into which fits the piston 53 connecting at its outer end with the bearing head 54 on the compressor piston 47, suitable cooperating ports being provided in the cylinder and in the bottom plate 39 whereby when the compressor is in operation oil is pumped from the sump formed by the base 4 into the passage 55 lubricating the lower trunnion and the piston 47 and thence to the chamber 56 above the upper trunnion. From chamber 56 oil is led by passage 57 to the shaft and wrist pin bearings from which the escape of oil is restricted to provide a predetermined back pressure in the chamber 56. Plunger 60 fits loosely in the chamber 56 and carries the spring pressed valve stem 61 which when the plunger is raised by the pressure of oil being pumped engages its seat formed in the cap 62. Opposite sides of the valve seat connect respectively with the small passage 63 in the cap and with the pipe 64 whereby when the valve 61 is in its open position, compressed gas from the interior of the casing is admitted to pipe 64. This pipe leads to the under side of the plunger valve 31 which valve is-closed against the tension of spring 33 by the gas admitted to pipe 64. Thus it 1 will be seen that during the normal running of the machine the oil pressure holds valve 61 closed and valve 31 remains open but as soon as the machine comes to rest the loss in oil pressure allows plunger 60 to descend opening valve 51 to admit gas pressure to pipe 64 is coming up to speed the motor is thus re-- lieved bf much of the load and by the time'it has reached normal speed the oil pressure will have closed valve 61, whence valve 31 opens and normal operationis resumed.

1,7ae,esa

As the plan er 60 (see Fig. 3) descends, due to. loss of oi pressure incident to sto ping ot' the pump, the edge 66 closes the oi passage 57 and thereafter .the leakage'of oil past the plunger permits the further descent to the position illustrated. To insure the rapid and positive downward movement of the plunger I have provided it with the channel 67 WlllCh' is spaced from the edge 66 a distance substantially equal to the diameter of the oil passage 57 and is connected therewith by a small hole 68. lVhen the pump is restarted the amount of oil that can pass through this hole (38 is not suflicient to prevent pressure being built up beneath the plunger 60 to raise it and close valve 61.

Should a quantity of liquid refrigerant or lubricating oil be drawn up from the evaporator it will be prevented by means now to be described from immediately entering the compressor cylinder, where it might damage the compressor. It will be noted that the outlet passages 41 from chamber (see Fig. 4) are carried a to a point somewhat above the bottom of t e chamber so that a sump is formed in the bottom of the chamber below the intake ends of these passages in which the liquid may collect. The lower portion of the sump thus formed connects by the small passage 70 with one of the passages 41 to permit any liquid which may have collected therein to be drawn off gradually with the gas on its way to the compressor.

' The compressor cylinder 45, as already stated above, exhausts into the casing which encloses the mechanism. The exhaust valve igsee Figs. 3, 4 and 5) comprises the thin at plate 72 which is adapted to seat against the end face of the cylinder 45. The plate is retained and guided in its movement by the mufller casing 7 3 which isshown as rectangular in shape and as secured to the cylinder by screws 74. The valve plate 72 is resiliently held against the cylinder by spring means comprising the thin ring 7 5 which is slightly and evenly corrugated sov as to provide a series of staggered uniformly spaced points of contact on opposite sides respectively with the valve plate and with the casing. The exhaust gas having passed the valve into the mufller casing escapes therefrom throu h a number of small openings 76. At 77 have shown an additional spring between the plate and casing which sprin under certain circumstances, may be founc unnecessary; T

What I claim as new and desire to secure by Letters Patent of the United States is 1. A refrigerating machine comprising a gas tight casing, operating mechanism therein comprising a compressor, means for resiliently mounting the mechanism 1n spaced relation with the walls of the casing, an evaporator, a pipe connection between the compressor and the evaporator forming a pluinounte ,fcompressed refrigerant theremto, an evaprality of turns about the mechanism, and means comprising a tie between the turns for dumping vibrations thereof.

2. A refrigerating machine comprising an enclosin casing, a compressor yieldingly therein and arranged to exhaust orator, an inlet'pipe for the compressor having connection with the evaporator and having a yielding portion comprising a spiral surrounded by the compressed refrigerant, the turns of said spiral being arranged to drain toward said evaporator.

3. A refrigerating machine comprising an evaporator, a compressor of the type producmg a rapid intermittent movement of material through its intake, said compressor discharging compressed refrigerant into a chamher, an evaporator. a condenser connected between said chamber and said eva orator, an inlet pipe having connection witli the evaporator and having a yielding portion comprising a spiral surrounding the com ressor, and means providing a connection etween said pipe and said compressor, said means having formed therein a surge chamber for damp ng further progress of waves incident to said intermittent movement.

4. A refrigerating machine comprising an evaporator, a refrigerant com ressor, a connection therebetween, a valve 1n the connection, means for normally retaining said valve in open position so that the refrigerant may pass therethrough during the operation of the compressor, and means independent of the pressure in said'connection for causing said valve to close when the compressor comes to rest.

5. A refrigerating machine comprising an evaporator, a refrigerant compressor, a connection therebetween, a valve 1n said connection arranged to be closed by com ressed refrigerant, resilient means for he ding said valve in open position, and means independent of the pressure in said connection for admitting compressed refrigerant to close said valve whenever said compressor comes to rest.

6. A'refrigerating machine comprising an evaporator, a refrigerant compressor, a connection therebetween includin a surge chamber, a valve in said surge c amber, means for normally retaining said valve in open osition so that the refrigerant may pass t erethrough during the operation of the compressor, and means for utilizing the pressure of the refrigerant on the high pressure side of said compressor for closing said valve wherever said compressor comes to rest.

7. A refrigerating machine comprisin an evaporator, a refrigerant compressor inc uding means for producingean auxiliar fluid pressure, a connection tween sai compressor and said evaporator including a surge chamber, a valve in said surge chamber, means for normally retaining said valve in open I position so that the refrigerant may pass therethrough during the operation of the compressor, and means including a second valve controlled by said auxiliary fluid pressure for utilizing the pressure of the refrigerant on the high pressure side of said compressor for closing said valve in said surge chamber whenever said compressor comes to rest.

8. A refrigerating machine comprising an evaporator, a refrigerant compressor having a lubricating pump, a connection between said compressor and said evaporator including a surge chamber, a valve in said surge chamber, means for normally retaining said valve in open position so that the refrigerant may pass therethrough during the operation of the compressor, and means including a second valve controlled by the pressure of said lubricating pump for utilizing the pressure of the refrigerant on the high pressure side of said compressor to close said valve in said surge chamber whenever said compressor comes to rest.

In witness whereof, I have hereto set my hand this 3d day of February, 1927.

CHRISTIAN STEENS-TRUP. 

